There are a few drawbacks, most notably, the comments from previous posts are still tied to the Tumblr website, because Tumblr doesn’t use slugs (e.g. “migration-to-github-io”) for its webpage names, instead it uses some random number generator for keeping track of posts, e.g “post/72680703972”. And because Disqus uses the URL from the post to map it back to its database, and I couldn’t get the original mapping :( So comments for old posts will be back on Tumblr.